The Microsoft Web Platform includes the Microsoft Web Platform Installer (WebPI), and the Microsoft Web Application Installer (WebAI).

Microsoft Web Platform Installer (WebPI): simplifies the setup and acquisition of the products that make up the Microsoft Web Platform. A single install gets you the software you need to build and run a complete web solution on the Microsoft stack.

The Microsoft Web Platform Installer Beta is a free tool that makes it simple to download and install the latest components of the Microsoft Web Platform, including IIS7, SQL Server Express, .NET Framework and Visual Web Developer.

To help you stay up-to-date with product releases, the Web Platform Installer Beta always contains the most current versions and new additions to the Microsoft Web Platform.

Microsoft Web Application Installer (WebAI): provides easy access to popular community PHP and .NET web applications for Windows Server. Supported applications include: DotNetNuke, Drupal, Gallery, Graffiti, osCommerce, PHPBB, and WordPress.

The Microsoft Web Application Installer Beta downloads, installs and configures top ASP.NET and PHP community Web applications to run on your Windows Server.

The  Microsoft Web Application Installer Beta handles all the detail work for you, including configuring IIS 7, ensuring your computer has the required prerequisites, and managing where to download the application.

Learn all about it here

Joel